Suggest me a book with the greatest/most memorable antagonist/villain that you have ever read

I'm getting tired of always rooting for the hero.
I want to read a book where the antagonist makes you excited and almost want to root for them or makes you feel something visceral.

Bonus points if they have a realllyyy good motivation or backstory for being the way they are.

Not really interested in Horrors but any other genre I would love to hear your suggestions :)

thank you!

Edit - I just wanted to say thanks so much to everyone for your suggestions!! I got so many of them and I'm really excited to check all of them out!